The present application relates generally to a self-dispersible particle or powder, compositions containing the self-dispersible particle or powders, and methods for forming such particles or powders and compositions containing the particles or powders. Particularly useful compositions that may contain the self-dispersible particles or powders are cosmetic compositions.
Metal oxides such as titanium dioxide, zinc oxide, and iron oxides have been employed as attenuators of ultraviolet light in applications such as sunscreens, paints, coatings, and plastic films and resins. The metal oxide is often present in the end-product as dispersed particles, so better dispersion mechanisms are always needed.
Metal oxides of large or small particle size, even when coated like methicone and silane, are known to have poor dispersibility in esters, vegetable oil, mineral oil and hydrocarbons. Poor dispersibility can adversely affect UV attenuation and transparency in sunscreens and color strength in pigments, as well as skin feel and formulation stability.
Dispersion of micro metal oxides have been disclosed in literature. The process disclosed in the literature requires milling the metal oxides, and the milling process involves equipment that is not often available to many formulators. In many cases, only mechanical mixers or homogenizers are available to the formulator of the end-product to disperse particulates. Even when a milling process is available, the variation of formulation and complexity of ingredient will make the formulation of a proper dispersion difficult. In addition, cosmetic formulators are often not familiar with dispersion technology, and do not have time to find out the best dispersion and best use level for their system.
Therefore, there exists a need to improve the dispersibility of the pigment, for example metal oxides, so that the pigments give the desired performance even in the absence of the milling that requires extra machine and process.